CVE-2024-39477 mm/hugetlb: do not call vma_add_reservation upon ENOMEM

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: do not call vmaaddreservation upon ENOMEM sysbot reported a splat 1 on unmaphugepagerange. This is because vmaneedsreservation can return -ENOMEM if allocatefileregionentries fails to allocate the fileregion struct fo...